Also, from Control Panel> Action Center, Change User Account Control Settings, verify that the slider is not set to "Never notify." If User Account Control is set to "Never notify" Protected Mode and Enhanced Protected Mode can't be enabled.

With 64-bit IE11 on Windows 7, if Protected Mode and Enhanced Protected Mode are both enabled, you will get 64-bit manager processes and mostly 64-bit tabs. The content of some webpages may result in 32-bit tabs. This will be automatic based on the content
of the webpage.